Electronic system employing plural processing stations for issuing airline boarding passes while effecting seat assignments, and generally for parcelling elements of an ordered set

ABSTRACT

A digital, electronic system for issuing airline boarding passes, while effecting aircraft seat assignments, employs a central processor unit connected via a plurality of system busses to a plurality of parallel connected keyboard units each having a boarding pass enscribing alpha-numeric printer associated therewith. The central processor includes a circulating memory for storing information characterizing the availability of seats for the particular aircraft in service, while the keyboard units include a lamp matrix for displaying seat availability in a section (zone) of the aircraft selected by a passenger. The central processor sequentially and cyclically polls all on line keyboard units, accommodating all proper seat requests while maintaining real time supervision over the memory contents and the keyboard units. Seat assignments are automatically printed, together with other pertinent information, on a boarding pass when a seat is selected.

0 United States Patent 1 [111 3,750,103 Angus et al. 1 July 31, 1973ELECTRONIC SYSTEM EMPLOYING 3,134,016 5/1964 Connolly 340 153 x L LPROCESSING STATIONS FOR 3,5 ,21,57 3/1926 (S3cl1otttlf 340/ 153 ISSUINGAIRLINE BOARDING PASSES 3, 4, 8 1 I19 9 reen um 340/153 WHILE EFFECTINGSEAT ASSIGNMENTS,

Primary ExammerHarold l. Pitts AND GENERALLY FOR PARCELLINGAttorney-Sandoe, Hopgood & Calimafde ELEMENTS OF AN ORDERED SET [75]lnventors: David R. Angus, Flemington, N..l.; [57] ABSTRACT wmllm Reidsmllh'vlmllv D806", A digital, electronic system for issuing airlineboarding Connpasses, while effecting aircraft seat assignments, em- [73]Assign. General Computing Equlpmem ploys a central processor unitconnected via a plurality Corporation Princeton, NHL of system busses toa plurality of parallel connected keyboard units each having a boardingpass enscrlbmg Filed: 1970 alpha-numeric printer associated therewith.The cen- {211 APPL 102,629 tral processor includesa circulating memoryfor storing information characterizing the availability of seats for theparticular aircraft in service, while the keyboard US. Cl- R, R unitsinclude a lamp matrix for eat availabil- [51] Int. Cl. H04q 1/00, H04q3/00 it i a section (zone) of the aircraft selected by a of Search R, Rengen The central processor sequentially and cyclically polls [56]Reierences Cned all on line keyboard units, accommodating all properUNITED STATES PATENTS seat requests while maintaining real timesupervision 2,542,890 2/1951 Basu 340/153 over the memory contents andthe keyboard units. Seat 3,675,204 7/1972 Miehle 340/286 assignments areautomatically printed, together with 25687 9/1951 Mcwhme' 340/153 otherpertinent information, on a boarding pass when 2,594,960 4/l952 May340/153 X a seat is selected 2,910,238 l0/l959 Miles. 340/153 X3,071,753 1/1963 Fritze 340/153 '21 Clalms, 12 Drawing Figures CountersOff 31 5 20 5 Pre- Res. Mon-Set 307 303 304 000 0000 000 BO iUI'JOQ I ol I 0 307 5 i E] I I I i [J E l l I 9 I I D 304 i El ET I 3"; U

I ITI l I I l L0 l Release' 312 Key Board Unit 30l PAIENIEU JUL 3 1 msSHEET 1 OF 7 ATTORNEYS Circulating Memory Contents owgzons a nowgzonssf-- /L FIG. 4A

. CD00 1 n n n n L II FIG. 4C

L rm I'L l FIG. 4 D

CPCO V L I I I I g I l I I I I I I r- =6 7 CPU I KU Sfofus Zone Row 1Seof Selects Reported Information Information Information Cons. To CPUTransfer Transfer Tronsfer FIG. 48

INVENTORS DAVID R. ANGUS WILLIAM REID SMITH-VANIZ ATTORNEYS ELECTRONICSYSTEM EMPLOYING PLURAL PROCESSING STATIONS F OR ISSUING AIRLINEBOARDING PASSES WHILE EFFECTING SEAT ASSIGNMENTS, AND GENERALLY FORPARCELLING ELEMENTS OF AN ORDERED SET This invention relates to digitalcomputing systems and, more specifically, to digital circuitry employed,for example, as an aircraft boarding pass-seat assignment dispensingsystem.

BACKGROUND OF THE INVENTION Procedures for parcelling available, uniqueelements of an ordered set have presented difficulties in practice andhave often been conducted in a less than satisfactory manner. An exampleof set parcelling comprises the procedure at an airport boarding gate,where numbered seats for an aircraft are distributed to passengers uponissuing a boarding pass. For any given flight, some model or tubularlisting of the available aircraft seats is prepared, the seat arrayvarying for the particular aircraft equipment, its modifications,dedicated and preassigned seating, (e.g., for stewardess), and the like.An attendant at the gate typically processes passenger and seriatim,issuing boarding passes and assigning seat cations on an availabilitybasis, keeping a running record of those seats which remain available.

However, this current practice suffers several deficiencies. First, andimportantly from the standpoint of passenger convenience, the procedureis amenable to only a single boarding station where the seatavailability information is available. This results in passenger delayin boarding, a difficulty which has become more pronounced when severalhundred people board the newer and larger commercial aircraft.

Multiple passenger processing stations are one solution to expeditingpassenger boarding. However, to prevent inadvertent multiple assignmentsof the same seat, the aircraft seats must be prealloted among theseveral stations, resulting in a lesser choice for each passenger.Further, unless the passengers are processed at the stations in theexact proportions as the seat allotment, a heavily loaded aircraft willgive rise to situations where some stations are effectively removed fromservice after their seat allotment is exhausted, thus delaying boarding.In addition, where plural boarding stations are employed, it wouldheretofore have been difficult to maintain a running total of passengersboarding the aircraft and more specifically to maintain a record ofpassenger count in the several tariff classifications of the aircraft(e.g., first class, tourist and the like), to serve as a verificationfor an actual count made onboard, and for other business purposes.

The set parcelling process has been described above in an airlinerboarding-seat assignment context. Other practices of this procedure areof common experience, e.g.. room assignment in hotels and motels,theater and sports ticket distribution, and sales-inventory maintenanceof ordered, nonfungible merchandise, among many others.

It is thus an object of the present invention to provide improvedapparatus for distributing elements of an ordered set.

More specifically, it is an object of the present invention to providedigital electronic circuitry for allotting elements of an ordered,programable set at a' plurality of stations therefor, the stations eachhaving undivided access to the full set, and wherein no element of theset can be coincidentally seized by more then one station.

It is another object of the present invention to provide a multiplestation set distribution system wherein cumulative totals are developedand displayed at all stations for each of plural subset classification.

It is a still further object of the present invention to provide setparcelling apparatus employing central processing equipment and aplurality of system busses, wherein plural parcelling stations asrequired may be connected in parallel to system bus lines.

Yet another object of the present invention is the provision of multiplestation, set distribution apparatus, wherein each station includes acontinuously updated data outputting peripheral unit for providing aprinted record upon allotting any set element.

It is another object of the present invention to provide multiplestation set distribution equipment for automatically seizing a portionof the set during availability interrogation to ensure uninterruptedaccess to the seized set portion.

It is a specific object of the presnet invention to provide an improvedvehicle boarding pass seat location assigning system.

SUMMARY OF THE INVENTION The above and other objects are realized in aspecific, illustrative embodiment thereof, employed to issue airlineboarding passes while effecting aircraft seating assignments andpassenger count by class of service. The system arrangement includes acentral processor unit which periodically and cyclically communicatesvia system busses with a plurality of passenger accommodating stationseach comprising a keyboard selector switch assembly and display unit,and an alphanumeric printer associated therewith.

The central porcessor includes a circulating memory for storing digitalinformation characterizing the availability of all seats on theaircraft. The processor also includes the system clock, circuitry forsequentially and bilaterally polling the several keyboard stations on atime multiplexed basis, and logic circuitry including, inter alia,apparatus for selectively modifying the memory contents, and forenabling the system printers.

Each keyboard unit includes an array of lamps for indicating the statusof all seats in a section (herein: zone) of the aircraft selected by anarray of zone selector switches. This permits a passenger to select adesired area of the aircraft for viewing seat availability. Anilluminated and dark lamp in the lamp array respectively representavailable and unavailable seats, and an intermittent flashing glowidentifies a prereserved but unclaimed seat.

Information descriptive of the aircraft configuration is read into thecirculating memory to define the initially available seat configuration.Passengers at the several system stations request a display of a portionof the airplane within their tariff classification, and a latchingdisplay of the requested area is initiated in the keyboard unit at thatstation. The display request, in common with all other communication andsignaling between a keyboard unit and the central processor, isaccommodated on a time-shared basis. However, the cyclically repeatingstation scanningrate is made sufficiently fast (e.g., fifteen times asecond) such that results appear instantaneous within the limitspassenger perception.

A passenger viewing the display selects a row within his chosen zone,this being accomplished via a plural row selection switch. That row iseffectively seized for the request issuing station, making itunavailable to any other station. This prevnets interference with seatselection, as where a group of passengers desire adjacent seating.Finally a seat is selected by seat selector switches on each keyboardunit.

The printer at the operated keyboard unit tracks the active zone, rowand seat selector switches. When an available seat is requested, aboarding pass inserted in the printer is marked with the selected seatidentity without any delay otherwise attendant to rotating printercharacter wheels. The central processing unit responds to a seatselection by designating that seat as unavailable in the circulatingmemory.

Counters are provided at each station and interconnected by systembusses to track the number of seats issued for each class of service byany of the keyboard units.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other features andadvantages of the present invention are realized by a specificillustrative embodiment thereof, discussed in detail hereinbelow inconjunction with the accompanying drawing, in which:

FIGS. lA-lE depict in schematic-form an aircraft boarding pass-seatassigning digital system embodying the principles of the presentinvention;

FIG. 2 illustrates the operative panel of a keyboard unit employed inthe system of FIGS. IA-lE;

FIG. 3 depicts a boarding pass prepared by the system of FIGS. lAlE;

FIGS. 4A-4D are timing diagrams characterizing the system of FIGS.lA-lE;

FIG. 5 illustrates the spatial arrangement of FIGS. lA-lE.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIGS. 1Athrough 1E, hereinafter referred to as composite FIG. 1, there is shownin schematic form a digital electronic system for issuing airlineboarding passes, and for effecting'aircraft seat assignments. Thearrangement comprises a central processor unit 100 connected via aplurality of system busses 200 to a plurality of operator consolestations 300 300,, each of which includes a keyboard unit 301 and adigital printer 302.

In operation, the central processing unit 100 sequentially andcyclically communicates with (polls) the several on-line attendedconsoles 300 on a time-shared basis. The scanning rate between thecentral processor and the console is made sufficiently rapid (e.g.onefifteenth of a second) such that all data requests made by anattendant at a console appear to be instantaneously operated upon from ahuman perception frame of reference.

The operative panel of a keyboard unit 301, and the printer 302associated therewith, are shown in FIG. 2, and a boarding pass issued bythe composite FIG. 1 system, and by a system printer 302 in particular,is shown in FIG. 3. The pass 10 has illustratively printed thereon adate field 14, a flight number identification field l6, and a seatdesignating field 18 comprising a section (zone) of the aircraft, a rowwithin that zone and a seat within the row. The boarding pass 10 is ofrectangular form for tourist class service, and has a removed cornerportion 12 for first class service.

The console 300 located at each of the several passenger processingstations includes an array of lamps 303 disposed in matrix form (seeFIG. 2), each of the lamps conceptually representing a correspondingseat in a selected zone of the aircraft. Each row of lamps correspondsto a row of seats in a zone of the aircraft selected by a plurality ofzone selector switches 307,. The number of lamps in both lineardimensions of the array 303 is made sufficiently large to accommodatethe largest aircraft seating capacity and arrangement.

keyboard unit 301 includes a mode selection switch 305 for selecting amode of operation desired for the keyboard unit 300. When servicingboarding passengers in a routine manner, the mode switch 305 normallyresides in an OPERATE" position. With the switch 305 so disposed, apassenger indicates to the console attendant his preference for seatingin a particular zone of the aircraft. The operator then depresses one ofthe set of zone selection switches 307 corresponding to this aircraftsection. Responsive to this zone request, and during the time intervalwhen the console station is next connected to the central processor unit100, the lamps 303 on the keyboard 30] become selectively illuminated todepict seat availability for all seats within the selected airplanesection. In particular, and in accordance with illustrative seatavailability signaling, an illuminated bulb identifies an availableseat; a dark bulb signifies a seat which has already been allotted; anda flashing lamp denotes a prereserved but as yet unclaimed seat.

Upon viewing the seat availability pattern the passen ger next indicatesto the attendant a row within the selected zone in which he desires tosit. The attendant then depresses a corresponding one of an array of rowselector switches 309. This has the operative effect (when the rowrequest is next accommodated by the central processor unit of seizingthe selected row for the row requesting console 300 such that no otherconsole may claim a seat in that row. A lamp 304 included as an integralpart of each row switch 309 is illuminated to indicate that one of thekeyboard units is processing a seat request in that row, and that therow is therefore not available to any other station until suchprocessing has been completed. This mode of operation eliminates raceconditions between the keyboard units, and also permits a subscriber atthe console requesting that row to take a number of adjacent seatswithout having another console unit interrupt the desired contiguousseating pattern.

Finally a passenger specifies a particular desired seat within theselected row by depressing one of an array of seat selector switches31]. When the attendant then inserts a blank boarding pass form into aticket receiving orifice 370 of the digital printer 302 at that consolestation or if a pass was already present then), the desired seatlocation is stamped on the pass with other appropriate information, suchthat a ticket of the form shown in FIG. 3 is generated. The printngmechanism is adapted to continuously track the seat selector switches307, 309 and 311 such that the seat request is processed almostinstantaneously when the boarding pass is positioned in the printerorifice 370, and all conditions for seat allotment are satisfied. Thedate and flight information for the printer 302 is generated by settingthumb wheel switches 371 located on the printer.

The console unit includes two electrical counters 312 and 314 forcounting the total number of first class and tourist passengers boardingthe aircraft independent of which console station issued the boardingpasses. Accordingly, each time a boarding pass is issued at any of thesystem consoles 300, a signal is generated on one of the system buslines 200 to activate the appropriate one of the printers 312 or 314 ateach console station depending upon the class of service for theboarding passenger.

For a complete aircraft boardng cycle of operation for the compositesystem of FIG. 1, a mathematical model describing seat availabilitycharacterizing the aircraft for a given flight is read into a memorycontained in the central processor unit 100, either by re petitivemanual operation of the mode switch 305 and selector switches 307, 309and 311, by connecting a data input assembly 450 (e.g., a magnetic tapeunit) to one of the keyboard units 301. The counters 312 and 314 arecleared before passenger boarding commences, as by manually depressingcounter clearing buttons 315 thereon, and the thumb wheel switches 37]are set to proper positions.

The keyboard units 301, are electronically uniquely numbered andcyclically polled by the central processor unit 100. Integral to theseat reservation procedure, zone selection switches 307 are depressed atthe consoles 300, and seat availability of those aircraft zones isdisplayed on the lamp matrices 303 at the corresponding consoles. Whensufficient information has been inserted into any console 300, to selecta seat, viz., when a zone, row and seat switch of the switch arrays 307,309 and 311 are depressed; when the desired seat is available; and whena boarding pass form has been inserted in the orifice 370 of the printer302 at that station; the central processor 100 issues a print commandand allots the seat. The processor 100 also changes the status of thatseat in its memory so that the seat will not be redundantly issued.

The seat and lamp 303 display requests are processed during the portionof the overall cyclic scanning period when the console 300 requestingthe seat is functionally connected by the system busses 200 to thecentral processor unit 100. Further, each time a seat is issued by anyconsole 300, an appropriate one of the counters 312 and 314 at eachkeyboard unit 301 is advanced depending upon the class of serve for theissued pass.

Circuitry is provided in the system to provide various controlfunctions, and tr overcome human and mechanical errors, or changingcircumstances. For example, with the mode switch 305 in the ERRORposition, and a zone, row and seat switch depressed, the seatavailability information for the identified seat within the centralprocessor memory is returned to available status independent of itsformer state, e.g., when a passenger changes his preference. Similarlywith the console mode selector switch 305 in the manual set (MAN- SET)and prereserved (PRE-RES) positions, a seat fully identified seat by theswitch arrays 307, 309 and 311 is respectively made unavailable orreserved in the central processor memory;

Further a release lamp-actuator button 312 located on the keyboard unit301 is illuminated if an attendant engages a row switch to select a seatrow which has previously been seized by another console. An illuminatedrelease lamp 312 signals the attendant that he must depress the button312 to mechanically release the improperly depressed row selectionswitch any well known release linkage being employed between the button312 and the switches 309. correspondingly a lamp 313 is illuminated whena console 300 requests a seat which is not available, thus signalingthat another selection must be made.

The particular functioning of the several system circuit portionsconsidered by way of overview above will now be considered in detail,both as to their structure and their cooperative mode of operation. Thecentral processor includes a circulating memory for storing availabilityinformation characterizing all of the seats of a subject aircraft. Theprocedure for inserting this information into the memory 130, bothmanually and from an information storage medium, is discussed below. Thecirculating memory 130 comprises a delay line 134 receiving its inputfrom the output of a plural stage shift register 136. The output of thedelay line, 134, in turn, is supplied to the data input terminal of theshift register. Data is stepped through the shift register (and therebythe delay lines) at a rate determined by a system clock oscillator 101.The stored information thus repeatedly cycles through the delay lines134 and the shift register 136 at a rate given by the oscillatorfrequency.

The contents of the circulating memory 130, which serially appears atthe output of each and all of the shift register stages, is depicted inFIG. 4A. This information may be conceptually viewed as a series of databits charterizing the seats for each of the zones of the aircraft(assumed to be a maximum of six zones for concreteness), followed by aterminal memory portion 502 which does not contain seat availabilityinformation. When the memory portion 502 is in an operative positionwithin the circulating memory 130 for reading, viz., when this part ofthe memory contents circulates through the shift register 136 andappears at the output terminals thereof, the system effects itsadministrative chores. Important among these chores, and as discussed indetail below, during this interval a particular cone of the keyboardconsoles 300 is selected for all necessary servicing by the centralprocessor 100.

The memory contents for zone 3 of the aircraft, illustrative of theother zones, is shown in detail in FIG. 4A. The zone 3 information is inturn subdivided into a plurality of data segments associated with eachof the k rows within zone 3. The data corresponding to one of the rowswithin zone 3 viz., the row 1, is illustrated in detail in FIG. 4A andcomprises a first field 504, of four digits width, which identifieswhich, if any, of the consoles 300 has depressed its switches 307 309corresponding to row 1 of aircraft zone 3 to seize this row for seatselection, thereby rendering the row unavailable to any of the otherconsoles as discussed above. If the row is not being interrogated by anyconsole 300, the data portion 504 is blank (all zeros). The particulardigits, if any, located in the data field 504, uniquely correspond toand specifically identify one of the consoles.

The remainder of the information within the memory contentscorresponding to row 1,.zone 3 comprises a plurality of two bit byteswhich sequentially characterize the availability of a different seat inthe row. The data byte 506 is illustratively shown with the digitalpattern 01 which may indicate, for example, that the first seat in therow is available; the byte 506, is indicating that the seat is notavailable; and the byte 506 is to identify a prereserved seat. The lastbyte 506 of the row is shown as having a nonavailable seat. Since memory130 is designed to accommodate the largest anticipated aircraft, theterminal data fields in each of the row memory portions (and final rowswithin a zone) will typically be a sequence of zeros for any but thelargest aircraft.

To provide timing for the composite system, and to correlate the seatavailability information within the circulating memory 130 which ispresent at the memory output (the output of the plural stage shiftregister 136) with the seat having that availability, the systemreference oscillator 101 supplies an output clock pulse train to amodulo N counter 102. The number of states for the counter 102 (2) ismade equal to the number of digits stored within the circulatory memory130, so that the counter recycles at exactly the same rate as the memory130. Such synchronization is in part maintained by the oscillator 101,which advances both the counter 102 and the memory shift register 136.Each count state for the counter 136 uniquely corresponds to andidentifies to particular data within the memory 130. Thus, as describedin greater detail below, information regarding any seat may be derivedby examining seat availability signals at the output of the register 136at a time determined by decoding the output of the counter 102.

With reference to FIG. 4A, it is noted that the circulating memorycontents are cyclic in nature and comprise zone designations as majorsubdivisions; cyclicly repeating row designations within each zone (andbe tween zones) as a parameter of intermediate significance; and seatdesignation each cyclicly recurring for each row and for each zone asthe least significant designations. Correspondingly, the mostsignificant digits of the Modulo N counter 102 comprises zoneidentification signals; the digits of intermediate significancecorrespond to row designating information; and the least significantcounter output digits correspond to seat information. There is alsodeveloped a signal OSC/2 at the least significant counter stage whichcomprises an output square wave having a frequency corresponding to theoscillator I01 frequency divided by two for the purposes discussedhereinafter.

FIG. 4A depicts the information flow which continuously recirculates inthe memory 130. The figure may thus also be viewed in the time domain,wherein each stored information memory portion gives rise toperiodically recurring time intervals, while the entire memory contentscorresponds to a cylically recurring operational interval. As set forthin greater detail below, the processor 100 is connected in turn to eachof the system consoles 300 for a period equal to one full circulation ofdata in the memory 130. Console selection is effected during theadminstrative interval 502, and data transfer and other consoleservicing is then accomplished until the interval 502 next appears atthe output of the shift register 136. Thus, the on-line consoles 300 arepolled in turn for one circulation interval for the memory 130,beginning with the period 502.

The central processor 100 includes structure for generating a sequenceof control signals which are supplied to selected system busses 200 forcontrol and signaling purposes, and to interrogate the status of aselected console 300. This procedure occurs during the administrativeportion 502 of FIG. 4A. in particular, the central processor unitdevelops a single pulse (DSAMP FIG. 4B) which is impressed on a systembus 206 during the beginning portion of the repetitive time interval502. During the DSAMP pulse, each of the console keyboard units 301examines the digital pattern on a plurality of data busses 204 todetermine whether it is the console to be next serviced by the centralprocessor unit 100. The selected console 300 is thereby operativelyconnected to the central processor, and is conditioned to receivefurther commands from the central processor unit 100 while all othersystem consoles 100 remain inert.

The central processor 100 also generates a signal (FIG. 48) comprising afixed number of output pulses, e.g., the pulses 520 524, each of whichinitiates a different communicative function and mode of interactionbetween a console 300 and the central processor. During the pendency ofthe DSAMP pulse and the CPCO pulse 520, a particular system consolestation 300 is selected. During the interval between the trailing edgesof the pulses 520 and 521, the selected console 300 communicates itsoperational status to the central processor via signals impressed on thedata bus 204, e.g., digital signals indicative of the position of themode selector switch 305 (FIG. 2), and whether or not a boarding pass100 resides within the printer 302 of the selected console.

During the interval ending with the trailing edge of the pulse 522, zoneinformation (the identity of the depressed one of the zone selectorswitch array 307) is forwarded to the central processor unit 100.Similarly during the corresponding intervals bounded by the pulses 523and 524, the status of the row and seat switch arrays 309 and 311 at theoperative console is communicated to the central processor unit 100 viathe system busses 200.

The CPCO and DSAMP pulses are generated during each operative repetitivetiming cycle during which one of the consoles 300 is connected to thecentral processor 100. Each DSAMP pulse corresponds to one completecirculation of data in the memory 130, and one complete cycling of themodula N counter 102 (corresponding to 2 pulses supplied by the masteroscillator 101). Moreover the CPCO and DSAMP pulses are always generatedat the same relative time in the cycle when the circulating memoryportion 502 appears at the output of the shift register 136.Accordingly, the DSAMP pulse is generated by a timing-decoding network122 which decodes the requisite output configuration from the modulo Ncounter 102 which corresponds to the initial portion of the interval502. The timing-decoding network 102 may include for this purpose, forexample, a simple coincidence gate supplied with the most significantcounter 102 digits to decode the state corresponding to the memoryportion 502, and sufficient row and seat count digits to define anoutput pulse at the beginning of this period. Similarly, the CPCO pulsesmay be generated by decoding five intervals defined by the output of themodulo N counter 102, as by five coincidence gates each supplied withzone, row and seat digits from the counter 102. The timing decodingnetwork 122 thereby supplies five pulses via a plurality of leads 133 toa disjunctive gate 124, each of the pulses occurring at a timecorresponding to a different one of the pulses 520 524 of FIG.

4B. The output of the gate 124 will thus comprise the CPCO waveformshown.

As used herein, OR-gates are used for disjunctive logic, and AND-gatesare employed for coincidence logic. It will be readily appreciated bythose skilled in the art that NOR, NAND and other logic structures maybe used singly or in a proper combination to produce the required logicfunction.

To identify a selected one of the consoles 300, the central processorunit 100 includes a modulo C console selector counter 126, where 2" is anumber equal to or greater than the maximum number of console stations300 employed in the system. Once during each cycle for the systemcounter 102, and at the beginning of the time period 502, the timingdecoding network 122 supplies a pulse (as from a state decodingcoincidence gate) to the count input of the counter 126. The outputstate appearing at the several stages of the console selector counter126 is thus updated at the beginning of the administrative timinginterval 502 to select a console identified by a number cyclically onehigher than that selected during the previous cycle for the system.

During the console selecting interval of the time period 502 (during theDSAMP signal and the CPCO pulse 520 of FIG. 4B) the output signals fromthe counter 126 are gated by a gate 130 (e.g., formed of a plurality ofAND-gates 131) onto the data bus lines 204. As discussed below inconjunction with a console 300, the keyboard units 301 at the systemconsole respond to these signals for determining whether it is thestation to next be operatively connected to the central processor I00.

The structure in the keyboard units 301 and, in particular, the unit301, shown in detail in FIG. 1 and illustrative of the other like units,will now be considered with respect to implementing the controlfunctions depicted in FIG. 48. At the beginning of the administrativeinterval 502, the DSAMP pulse partially conditions an AND-gate 323 ineach of the keyboard units 301 connected to the system busses 200. Also,during the first CPCO pulse 520, an AND-gate 318 in each console ispartially enabled. The data bus lines 204 are connected to the remaininginputs of the AND gate 323 by a like plurality of switching elements 322each of which connects one of the lines directly or via an invertor 324to the corresponding ANDgate 323 input, the selection being made by thesetting of a transfer switch 325. Accordingly, the setting of theswitches 325 in the switch units 322 determines the binary numericalidentity of the console 300. Thus, for example, if all of the switches325 in the switching units are connected to the data bus lines directly,the AND-gate 323 will respond to a console identifying digital patternof all digital l 's" (giving the station an identity of l l l l ordecimal sixteen where four console identity digits are employed).Similarly, with all switches 325 connected to the output of theinvertors 324, the AND-gate 323 will respond to a digital pattern of alls" hence identifying the console as the decimal zero unit. Further,other mixed distribution of the switch settings are employed tocharacterize the console as designated by any intermediate 00-0 and ll-l, the zero designation not being used in practice.

When the console 300, is to be selected, its identification number ispresent on the data bus 204 and, accordingly, the gate 323 is fullyenabled during the DSAMP interval and supplies an output pulse at thistime which passes through an OR-gate 315 to the count input of aninitially reset divide-by-S counter 317. The output of the counter 317therefore advances to the one state (001 output) which is supplied to adigital decoder 325 and also to an OR-gate 326. The output of theOR-gate 326 becomes high by reason of the binary I digit at on-counterstage, this enabled output of the gate 326 comprising a console ME"signal signifying that the keyboard unit 301, is in fact the unitselected for processing selected by the central processor 100.

The voltage transient at the output of the switched OR-gate 326 developwhen the keyboard unit 301, is selected is differentiated by adifferentiator 329 thereby which supplies an inhibit control pulse to alatching gate 330. Responsive to the inhibit pulse supplied thereto, thegate 30 is momentarily rendered nonconductive, and blocks lamp 303energizing potential quiescently supplied from a source 240 thereof toone terminal of each lamp in the array 303 at that console keyboard by aconductor 352. This momentary interruption renders a plurality oflatching semiconductor switches 335 nonconductive to clear the lamp ofany seat pattern display.

Accordingly, following the DSAMP pulse and the CPCO pulse 520, theconsole 300, and particularly the keyboard unit 301, thereof, havedetermined that it is the selected station for the next cycle of centralprocessor operation and memory circulation, as manifested by thepresence of the ME signal; the l state for the counter 317; and thecleared state for the lamp matrix. It is observed, however, that systemoperation is sufficiently rapid that an observer viewing the lampensemble 303 cannot detect its reset, unilluminated state since a newpattern is quickly implemented, as discussed below.

As indicated in FIG. 4B, the selected keyboard unit 301, communicatesthe status of its mode selector switch 305 to the central processor unitin the interval following the CPCO pulse 520. In this regard the modeswitch 305 on the panel of the keyboard unit 301, employs a first seriesof normally open contacts 305,-l through 305 -1 one of which is closedwhen the mode switch resides in a corresponding mode selecting position.That is, for example, the contacts 305,-ll and only these contacts ofthe array 305-1 are closed when the mode switch is in the OFF position;contacts 305 -1 are closed when the switch is in the MAN-SET position,and so forth, the contact 305 -1 being associated with the OPERATE modeswitch position, which is the only position in which boarding passprinting is desired.

In the mode switch reporting interval following the control pulse 520 ofFIG. 4B, the I" count state for the counter 317 is decoded by a decoder325 which supplies an output potential at this time on a line 326connected to the 1" decode output terminal of the unit 325. This voltagelevel is supplied to one input terminal 329 of a digital encoder 330.The particular input terminal receiving the mode pulse depends upon theparticular one of the contacts 305-l which is closed, and therefore uponthe setting of the mode switch 305. Thus with the interconnectionpattern of the drawing, the upper encoder input 329 (marked l isenergized with the switch 305 in the OFF position; the encoder input 2energized with the switch 305 in the MAN- SET position (contacts 305 -1closed) and so forth.

position, but only when all of the conditions required for printing aboarding pass at printer 302, are met (print wheels set an output fromAND-gate 373; and boarding pass in the printer closed contacts 473).

The encoder 330 produces a digital encoding (e.g., BCD code) on an arrayof output lines 331 which identifies the particular input terminalthereof which has been energized. The digital pattern on the outputlines 331 then passes without change through data converging OR-logic332 and is impressed on the data bus 204 for communication to thecentral processing unit 100.

The timing decoder network 122 in the central processor unit 100produces a timing signal disposed within (or concomitant with) theconsole status reporting interval of FIG. 48, this signal beingdeveloped on a line 194 which enables a gate 121. The opened gate 121thus passes the encoded mode switch signals on the plural data buss 204conductors to a mode register or latch 190 which attains a state givenby these signals. The gate 121 may comprise a plurality of AND-gatessuch as that shown for the gate 130. It is observed at this point that aplurality of'gates 120, 119, 118 and 130 are blocked at this time, andthus the data on the bus 204 passes only to the intended register 190.In a like manner, and for the purposes discussed below, these systemgates are opened at differing times or from one another to performappropriate data distribution functions associated therewith. In thismanner system signals may translate between sending andreceivingelements without interference from other system elements connected withthe buss group.

A digital decoder 192 is connected to the mode register 190 andenergizes one of the outputs thereon dependent upon which particularoperational mode is being effected by the system as represented by thestored mode switch encoding. The voltage level present at one and onlyone of the decoder 192 output terminals provides a record for theduration of a full operative cycle for the central processor unit 100which identifies the mode of service requested of the central processorunit 100 by the selected keyboard unit 301,.

Following the second CPCO pulse 521, the counter 317 in the console 301advances to a count of two, which is decoded and produces an outputsignal on a line 327. The line 327 is connected to one terminal of aplurality of normally open contacts 307 -1 through 307,-l with one ofthese contact pairs being closed depending upon which of the zoneswitches 307 (FIG. 2) is depressed. Thus, for example, where the zoneselector switch 307 is depressed when a passenger indicates that hedesires to sit in zone 1 of the aircraft, the contacts 307,-1 areclosed.

During the zone information transfer time interval shown in FIG. 48(following the pulse 521), the signal on the conductor 327 passesthrough the closed one of the contacts 307-1 to one of the encoder 330input terminals 329. The encoder 330 produces a particular and distinctoutput encoding responsive to the particular energized input terminalthereof. The output encoding passes through the gate 332 onto the databus 204 for transfer to the central processor unit 100.

During the zone information transfer interval, the timing decodingnetwork 122 supplies a signal to a conductor 193 for opening the gate118, thereby inserting the encoded zone information into a zone register116. The output from the zone register 116 is supplied as one digitalinput quantity to a zone digital comparator 109.

In a similar manner row information is transferred to the centralprocessor during the interval therefor shown in FIG. 48. During this rowinformation period the signal present on a conductor 328 passes throughone of a plurality of row contacts 309,4 through 309,,- l dependant uponwhich one of the row switches 309 (FIG. 2) have been depressed if any.The contact closure in the group 309-1 is encoded by the unit 330,impressed on the data bus 204, and passed through the gate 119 (enabledby a timing signal on conductor 192) to be stored in a row register 114.The output of the row register 114 is supplied as one set of inputdigits to a row digital comparator 107.

Similarly, following the CPCO pulse 523, an energized decoder 325 outputconductor 329 passes a voltage to a closed contact pair of a group 311-1through 31 l,,,-1 depending upon which one of the seat selectionswitches 311 (FIG. 2) has been depressed, if any. The seat switchinformation is encoded, impressed on the data bus 204, and passesthrough an enabled gate 120 to a seat register 112, and therefrom to aseat digital comparator 105. Thus, following the pulse 523, allnecessary information characterizing the selected console 300, has beenregistered in the central processor unit 100, viz., the mode of servicedesired, and the identification of the zone, row and seat if in fact allthis latter information has been entered at the console.

Less than this full quantum of information may be communicated to thecentral processor unit 100. For example, during the milisecond intervalwhen the station 300, is polled by the central processor unit 100, theremay as yet have been no seat and/or row selection made. When thiscondition obtains, as is the general case, no meaningful seat selectionoperation will be effected, although the polling cycle is useful ingenerating a desired seat availability display.

' The final CPCO pulse 523 advances the state of the counter 317 to acount of five, thereby producing an enabled HARK signal on a decoder 325output terminal. This active state I-IARK signal characterizes thekeyboard unit 301 as residing in an operational state, and is utilizedas an enabling signal for various system purposes considered herein.

The zone comparator 109 is supplied with the most significant digits ofthe system counter 102 which identify the aircraft zone then presentedat the output of the circulation memory 130. When the aircraft zonerequested by a passenger by a zone switch 307, as stored in the zoneregister 116, matches the zone present at the circulating memory outputa Zone Match (ZM) sig nal is produced by the comparator 109. Similarly,Row Match (RM), and Seat Match (SM) signals are respectively generatedwhen, and only when, the row selected by the switch array 309 and 311(stored in the registers 114 and 1 l2) identically match the seat androw identified by the digital output of the counter 102. An AND- gate110 is provided to generate an All Match (AM) signal when the specificseat in the aircraft identified by the contents of the register 112, 114and 116 corresponds with the output of the counter 102. It is observedthat when the register 112 contains seat information (one of theswitches 311 engaged at the operative console) the seat match signal isgenerated once for each row when availability information for that seatis available at the output of the memory. Similarly, a

row match signal is developed during processing for each zone of theaircraft.

The manner in which the array of lamps 303 at the keyboard unit 3011 isilluminated in accordance with seat availability in an area of theaircraft selected by an activated zone switch 307 will now beconsidered. When one of the zone switches 307 at the illustrated console300 is depressed, information identifying the desired zone is entered inthe register 116 at the processor 100 when the console is next polled.Accordingly the zone comparator 109 generates a Zone Match output signalwhen availability information for that section of the aircraft flowspast the memory output terminals. This zone match signal partiallyenables two AND-gates 150 and 152 during the time interval when seatinginformation for the requested zone is accessible. The gate 152 has itsother input connected to the OSC/2 signal, and thus the output from gate152 (CDCO signal) comprises the clock signal at one half the clock ratewhich is present only when the desired zone is present at the memoryoutput. FIG. 4C depicts this CDCO signal, it being assumed that theaircraft zone 3 has been selected by a console operator. The pulses inFIG. 4C are generated in synchronism'with every other output fromoscillator 101. Thus, one pulse appears in the CDCO pulse stream foreach seat in the desired zone, since two stored information bits (andthereby two oscillator pulses) are required for each seat.

The seat availability information stored in the memory 130 comprises twodigital bits for identifying the three possible seat states. This seatinformation is sensed in parallel from the upper two shift register 136stages shown in the drawing. If the second identifying digit is a one(from the second register stage) indicating that the seat is available(see the seat availability code given above), an OR-gate 147 isactivated and switches the AND-gate 150 toproduce a pulse at the outputof the gate 150 (CDVO signal). The presence of this video signal willturn the appropriate seat status light 303 on in the console 300 in themanner discussed below. When the contents of the two upper register 136stages are the seat is unavailable, and no signal is supplied to theOR-gate 147. Accordingly, when this condition obtains, the AND-gate 150is not switched and a zero level signal appears at the output of thegate 150 during the concomitant CDCOpulse. The absence of this pulsewill result in a corresponding console lamp being off.

In accordance with the lamp state code, a one in the first of the twostatus bits (from the upper shift register stage) is supplied to anAND-gate .146. The other input of the gate 146 comprisesthe output of adecoder 133 which is driven by the most significant or overflow signalof the station selector counter 136 and further counter stages 132. Thecounter 132 advances its state every time each of the line systemshasbeen polled. Thus, the AND-gate I46 isenabled by the counter and decoder132 and 133 only during selected polling cycles for the centralprocessing unit l00, and only during these cycles is the prereservedseat status signal allowed to pass through the AND-gate 146, the OR-gate147 and the AND-gate 150 to enter the CDVO video digit streamto turn ona lamp in the matrix arrayq303. Hence where a seat has a prereservedstatus, its corresponding Finally regarding the transfer of lampinformation to the keyboard unit 301 information is provided toselectively illuminate a lamp 304 in a switch 309 to indicate that thecorresponding row has been seized by one of the keyboard stations. Tothis end, a decoder 103 is connected to the seat digits of the counter102 and repetitively provides a Seat Zero (SZ) output signal to identifythe time when the digits identifying a station which may have seized arow (the field 504 of FIG. 4A) reside in the upper four shift registerstages 136. This input is supplied as one enabling timing input to aAND-gate 145. When a row has been seized, the identity of one of thatstation, including at least one nonzero digit, is contained in the upperfour shift register stages. Accordingly, an OR-gate 143 is enabled andswitches the AND-gate 145 to generate a video pulse through the OR-gate147 and AND-gate 150. This pulse is employed at the keyboard unit 150 toturn on the lamp 304 in the appropriate illuminated push bottom switch309.

This composite CDVO lamp video information signal is shown in FIG. 4D.As a general proposition. each of the pulses in the CDCO timing pulsestream will correspond to a particular lamp in the matrix array 303these CDCO being employed at the console to scan the lamp matrix. Whenan active level CDVO signal is present during a CDCO timing pulse, thecorresponding lamp of the array 303 is turned on. Conversely, theabsence of A CDVO pulse during a CDCO timing signal will give rise to adark lamp.

the particular manner in which the lamp array 303 is illuminated willnow be considered. The HARK signal at the operative keyboard unit 301 ispresent during the interval when the zone I zone 6 information (see FIG.4A) is serially present at the output of the circulating memory 130. Afortiori, this signal is present during the zone 3 data flow this beingthe section of the aircraft assumed to have been requested by thepassenger. Accordingly CDCO pulses (FIG. 4C) developed during zone 3timing are passed through an AND-gate 352 in the unit 301 and advance aninitially cleared seat-row counter 341. Accordingly, the signals presentat the counter terminals contain information sufficient to identify aparticular set in the aircraftin the same manner considered above forthe counter 102 at the central processor 100. The video information,i.e., the CDVO pulses which control the lamp state, are similarly passedduring zone 3 timing through an AND-gate 345.

The most significant bits at the counter 341 ouptut correspond to rowinformation which is decoded by a row decoder 343. The decoder 343partially enables one of a series of AND-gates 348 348,,- depending uponwhich rowin the aircraft zone 3,is then being processed. The gates 348are sequentiallyenabled in turn (348, through 348 as the state of thecounter advances. Similarly, a seatdecoder 342 decodes the outputs'fromthe least significant counter stages. The decoder .342 partiallyenables-one AND gate 350 associated with a seat (column) of thematrix303, thegates 350, 350 being cyclically energized in turn as thecounter 341 advances.

One row oflamps in the lamp;matrix array 303 is shown in thedrawing,,eachof these lamps being connected between a lampenergizingpotential on the conductor 352-andground via a controlled latchingswitch 335,'e.g., of asilicon controlled rectifier type.Assuming'these'lamps to be in the first orupper row of the array 303,the output of the AND-gate 348, is coupled to one input of each of theAND-gates 350 and partially enables these AND-gates when and only whenrow 1 information (during zone 3) is signaled by the counter 341 and,moreover, only when the CDVO video signal indicates that a particularlamp in that row should be on. Thus, for example, the first lamp in thearray 303 is turned on by an output signal from the gate 350, triggeringthe associated electronic switch 335 when row 1 (a proper output fromdecoder 343) and seat 1 (a proper output from the decider 342) arepresent to identify the first seat in the first row of zone 3, and whenthe CDVO level is high to indicate that the seat is available. If theCDVO signal were low during this time, this lamp would be skipped andwill remain off. The other lamps in the first row are sequentiallyilluminated or not illuminated in turn as the least significant digitsof the counter 341 advance in count.

Subsequent rows of lamps in the array 303 are sequentially examined andtreated as above when the count in the most significant counter 341stage is advanced by the CDCO pulse train. Each of the subsequent lamprows is controlled by a different one of the AND-gates 348 whose outputforms one input of an array of AND-gates comparable -to the gates 350,the other inputs of these gates being the output of the seat decoder342. The above described apparatus therefore generates a display at thelamp array 303 at the keyboard unit 301, in accordance with seatavailability information stored in the circulating memory 130.

In addition to causing a display, the depressed zone switch in the array307 (FIG. 2) also causes a zone printing module 361 in the digitalprinter 302, at console 301 to assume the corresponding position. Forthe assumed case, the number 3" will reside in an operative printingposition. To this end, each of the zone selector switches 307,, includesa second isolated set of contacts 307-2 each having one terminal thereofconnected to ground. The other contact terminal is connected to adifferent terminal 366,, which are sequentially engaged by a rotatingprint module commutating member 367. Rectified AC line potential 365 issupplied across a module print head stepping relay coil 364 and acontrolled switch 362 to ground, the switch 362 being conductive unlessground potential is applied to the control terminal thereof via themodule commutator 367. The commutator 367 is thus stepped by theenergized coil 364 once during each half cycle of the AC power line (forfull wave rectification) to advance the next terminal 366. Thecommutator 367 is mechanically coupled to the operative module printhead so that the print characters similarly advance one position duringeach half cycle of the power line.

When the printer head reaches the desired position, in this case aposition with the number 3 disposed in the active position, thecommutator 367 engages the terminal 366 and is thereby connected toground by the closed zone switch contacts 307 -2. The commutator 367thus disables the controlled switch 362 and prevents any furthermovement of the print head during succeeding low cycles. The printingmodule 361 remains in this state as long as zone 3 in the aircarft isselected by the corresponding switch 307,, with the mod ule 361 being ina proper position to print the character "3". In a similar mannerprinter modules 370 and 372, respectively associated with row and seatinformation, automatically and continuously track the row and seatrequested by the passenger, these modules being controlled by secondcontacts 309-2 and 311-2 associated with the row and seat selectorswitches 309 and 311. The actuating mechanism for modules 370 and 372 isidentical to that for the module 361, and is not shown in the drawing.

The output of the commutator 367 in each of the zone, row and seatprinter modules 361, 370 and 372 is supplied as an input to the AND-gate373 via inhibiting input terminals thereof. Further, the AND-gate ispartially enabled by the line 326 during the keyboard status reportinginterval of FIG. 48 following the CPCO pulse 520. During this interval,when all three of the printer modules are in a proper printing position,the AND-gate 373 is fully enabled and provides an output signal to thiseffect at its output. When a boarding pass is in the printer 302,, aswitch 473 is closed, either directly through mechanical actuation by'aboarding pass 10 or indirectly via a pass-sensing photocell andphotodetector which selectively engages the switching contacts. With thecontacts 473 closed; when all print modules are at rest in a properposition to print zone, row and set information corresponding to thatselected by the switches 307, 309, and 31 I; and when the mode selectorswitch 305 is in the OPERATE position (closed contacts 305-5), theOPERATE mode encod-- ing signal is passed to the processor register 190to issue a seat and boarding pass 10 if all other requisite conditionsare met.

The printer further comprises additional modules 373 for printing fixed"information such as date and flight number. This information is enteredas by the thumb wheel switches 371 (FIG. 2) which directly ground thedesired module terminal.

It will now be assumed that a passenger has selected a zone, row andseat; that the corresponding switches of the switch arrays 307, 309 and311 have been depressed at the console 301,; and that a boarding pass 10resides in the printer 302,. During the time interval corresponding tothe period 502 of FIG. 4A when the console 300, is next polled, thecentral processor is advised that the mode switch 305 at the unit 301,is in the OPERATE position. The mode information enters the moderegister 190 and the seat, rowand zone designations are impressed in theregisters 112, 114 and 116. At the point during information circulationin the memory when available information characterizing the desired seatis present at the output of circulating memory 130, an All Match signalis generated by the AND-gate 110 to partially enable an AND-gate 180. Anoutput from the mode decoder 192 confirms that the mode switch was inthe OPERATE position and thus further partially enables the AND-gate180. Finally, if the seat is in fact available or pre-reserved asindicated by the output of the OR-gate 147, the gate switches andgenerates a timed output PRINT pulse on one of the data buses204'controlled as to duration by a timer 182.

At the keyboard unit 301, the PRINT pulse together with the HARK pulseswitch an AND-gate 380 which triggers a print cycle initiating solenoiddriver 382. Accordingly, current flows through a print solenoid coil 383to cause the printer 302, to print all appropriate information onthe-boarding pass 10 present in the printer orifice 370.

In addition to causing printing, the central processor unit 100 changesthe stored availability code for the selected seat then present in theupper two shift register 136 stages to the code to mark that seat asbeing unavailable. This is effected by the SDC output signal of the gate180 which writes zeros into the shift register stages, as via twoOR-gates of a shift register preset input terminal OR-gate array 141.Such functioning may alternately be affected by opening a gate 183 viaOR logic at this time.

Thus, by the above procedure, seats are assigned and boarding passes areissued with the seat designation printed thereon, while the contents ofthe circulating memory 130 are continuously updated as seats are taken.

The case where an attendant at one of the consoles 300 selects a rowwhich was previously seized by another station will now be treated. Acomparator 179 compares the identity of the console currently beingpolled by the central processor 100 (signified by the output of theconsole selecting counter 126) with the identity, if any, of a consolewhich has already seized the row as manifested by the four digits in theshift register 136 at the beginning of each row (the field 504 of FIG.4A). When such an improper condition obtains, i.e., when (l) the row hasbeen seized by a station (represented by the inverted output of anall-zero detector 174), (2) which is not the station 300 currently beingpolled (no match sensed by the comparator 179), and (3) the informationat the shift register output is being examined at the beginning of a rowas required for the field 504 (a Seat Zero (52) output from the gate 103in coincidence with the Row Match and Zone Match (RM) and (ZM) signal),an AND-gate 176 is switched and sets a release lamp flip flop 128 whichenergizes one of the data bus conductors 204. This signal in coincidencewith the HARK signal switches a gate 375 at the console 301, whichilluminates the release light 312 on the console panel (FIG. 2) actingthrough a controlled switch 383. This light advises the attendant thathe has selected an improper row, and he must release this row since itis currently available for seat selection only to another console.Similar apparatus (not shown) may be provided to actuate the lamp 313 toadvise the attendant that he has selected a seat which is not available.

By way of further function of an administrative nature, a gate 169 marksthe field 504 at the beginning of a row with the identity of a console300 seizing that row, identity information being supplied by the consoleselector counter 126. The information is passed through the OR-gatearray 141 to the shift register 136 under control of an AND-gate 120during the Seat Zero (82) interval (the period 504) at the beginning ofthe desired row signalled by zone match and row match signals when theseat is available (as indicated by all zeros initially present in thefield 504 sensed by the zero detecting gate 174). Further, circuitry isprovided to release a row, as when a passenger has changed his mind,e.g., where a row switch 309 is depressed (causing writing in a field504), followed by actuation of a different one of the row switches 309.To this end, an AND-gate 199 recognizes a coincidence between the polledconsole 300 and the identity of a station which has seized a row (datain the row field 504 during the seat zero signal), but whre there is noRow Match (RM). At such time, an output signal from the AND- gate 199enables a gate 183 to pass all zeros from a register thereof 182 to therow field 504 via the OR-gates 141 to again make this row available toany requesting station.

The system counters 312 and 314 at each console station 300 are employedto register the number of tourist and first class (and/or other tariffclassifications) boarding passes issued by any console 300. To this end,the output of the printer solenoid driver 382 at each console 300, e.g.,that in the printer 302, associated with the console 300,, is connectedby an isolation diode 401 to normally closed and open contacts 402-1 and402-2, and thereby to system counter buses 212 associated with touristclass service and 214 associated with first class service. When theoutput of the printer solenoid driver 382 provides a low impedance toground to energize the printer solenoid 383 in the printer 302 and whena tourist class boarding pass is being issued, current for the counter312 advancing coils 312a connected at each station of the bus 212 have apath from a source thereof to ground through the normally closedcontacts 402-1, the diode 401, and the driver 382 in the printer 302,.Accordingly, the count station for each of the counter 312 at allstations advances by one.

The printer includes a photo cell (not shown).and a photo detector 406which are optically isolated by the upper left corner of the boardingpass 10 for tourist class boarding passes 10. However, when a firstclass pass is being issued, the removed corner 12 permits the photosource to irradiate the detector 406, thereby energizing a relay coil402 which opens the contacts 402-1 and closes the contacts 402-2.Accordingly, at such time the system counter coils 314a are energized toadvance to the first class passenger counters 314 via the buses 214, thecontacts 402-2 and the diode 401 when printing is effected.

As a final system function, data must be read into the system. This maybe done manually on a seat by seat basis. For example, to mark a seat asavailable, an attendant places the mode switch 305 in the ERRORposition, and identifies a seat in the aircraft by depressing a zone,row and seat switch. When the console 300 is next polled by the centralprocessor 100, this information is loaded in the central processorregisters 190, 112, 114 and 116. Responsive to the stored ERROR mode,the mode decoder 192 at the central processor partially enables anAND-gate 250, the gate 250 being fully switched when availabilityinformation characterizing the identified seat is present at the outputof the shift register 136 as signalled by the All Match (AM) signal. Atsuch time, the gate 250 enables a gate 162 which passes the O1 seatavailable code from a permanent register 156 therefor, and enters thisseat availability status in the memory via the OR- gates 141. Similarly,a seat may be marked as unavailable for identifying a seat with theconsole mode switch 305 in the MAN-SET position, the unavailable 11"code being passed by a gate 160 to the shift register 136 for such asystem operation. Further, a gate 161 is operative to pass the l0prereserved code to the register 136 via the OR-gates 141 when a seat isidentified with the mode switch 305 in the PRE-RES mode setting. Thus,availability for an entire aircraft may be entered into the memory 130by changing the mode switch at one or more of the console stations 300on a seat by seat basis.

However, as a more expeditious way of entering data, a tape or otherdata storage medium, may be programmed'with the initial availabilityinformation for seats for various aircraft seating configurations. Thetape is loaded on a tape unit 451 having a tape drive and multi-trackread head. The data supplied by the tape unit 451, together with theremainder of a data inputting assembly 450, supplies signals via thedata buss 204 to the central processor unit 100 which in essenceduplicates the signal pattern which would be supplied if an attendantwrote seat availability information into the circulating memory 130 onan ad hoc basis in the manner described above. This informationcomprises, starting with the second time interval of FIG. 48, a modesignal for effectively defining seat availability, followed by zone, rowand seat information to identify a particular seat exhibiting thatavailability. The asembly 450 comprises seat, row and zone counters 452,454 and 456 which step through the array of seats in the aircraft, theoutput of the counters being gated onto the data bus 204 by gates 462,464 and 466 during the proper timing intervals under control of theoutput of 20 the timing decoder 325. The seat counter 452 is directlycycled by the ME signal generated each time the console 301, is polled,and is thus in position to characterize another aircraft seat, while therow and zone counters 454 and 456 are advanced by the output of adecoder 458 which is responsive to zone and row information stored onthe tape; Accordingly, the input as sembly 450 supplies, in sequence,mode information to the bus 240 via a gate 460 responsive the conductor326 being energized during the interval between the trailing edges ofthe CPCO pulses 520 and 521 of FIG.

4B; zone'information from the output of the gate 462 between the pulse521 and 522; row data via gate 464 between pulses 522 and 523; the seatinformation between the CPCO pulses 523 and 524 via the enabled gate466. The tape unit is stepped by the ME signals generated at thebeginning of console polling, such that a different seat isautomatically characterized as to availability by the data inputtingassembly 450 each time the console associated with the assembly 350,e.g. the unit 300, of the drawing, is polled. As an illustrativerepetition rate for the instant system, data for 15 seats may beentering into the circulating memory 130 each second from a singleconsole station. Accordingly, data inputting for even the largestaircraft may be effected in a mere mattero of seconds.

Finally, it is observed that all flip flops and other latch circuits maybe initialized at the central processor 100 and at the console 300 inany well known manner, e.g. by providing timing signals therefor fromnetwork 122; by differentiating the leading edge of the OSAMP pulse; andthe like.

The above described system arrangement has thus been shown to issueboarding passes for an aircraft while effecting seat assignments in apreferred, improved manner accommodating all requisite system functions.Any desird number of consoles 300 may be connected to the system busline to establish plural passenger processing stations, thusfacilitating passenger boarding without delay. Also, seating is effectedin an orderly manner with unlimited access at each station for all seatsin the aircraft, and where a single seat cannot be inadvertentlyassigned to more than one party.

It is again observed that the system arrangement discussed in detailabove may be employed for any application wherein uniquely identifiableelements of a set are to be distributed at a number of processingstations.

Illustrative of such operations, the circulating memory may be loadedwith information characterizing the availability of rooms in a hotel ormotel complex. Each room is uniquely identifiable by a series ofparameters corresponding to zone, row and seat location parameters forthe air line context. For example, rooms can be identified by roomnumbers formed of any number of digits, each of the digits thuscomprising a different set ordering parameter. Alternatively, the numbersystem of rooms may be by building, floor, wing and room number, or thelike. Any number of available status states or characteristics for suchrooms may be stored in the memory, e.g. available, taken, reserved,multiple occupancy, and view, among others. Further, the system countersmay monitor any desired information, e. g., total rooms taken, rooms bydifferent rate classification, or the like. Rather than the boardingpass 10 of FIG. 3, the system printer 302 would issue room assignmentdocuments.

It is to be observed that the above described system arrangement ismerely illustrative of the principles of the present invention. Numerousadaptations and modifications thereof will be readily apparent to thoseskilled in the art without departing from the spirit and scope of thepresent invention.

What is claimed is:

1. In combination in a digital electrical system for issuing airlineboarding passes and for effecting seat assignments in an aircraft, saidaircraft seats being identified by a zone designation, a row within azone, and a seat within a row, comprising a central processor, at leastone console, plural conductor system buss means connecting saidprocessor with each of said consoles, each of said consoles including amatrix array of lamps, a plurality of zone selector switches, aplurality of row selector switches, a plurality of seat selectorswitches, and a mode selector switch, console selector means forsequentially and cyclically selecting each of said consoles, a moderegister, means for encoding the mode selector switch position at aselected console, means for inserting said mode switch encoding signalsin said mode register, zone, row and seat registers in said centralprocessor, means for inserting signals representative of siad zone andseat switches assemblies in said console in said zone, row and seatregisters, respectively, a circulating memory for storing and cyclicallypresenting at output terminals thereof signals indicative of theavailability of all aircraft seats, a system oscillator and counter foridentifying the information present at said circulating memory output,and means responsive to an aircraft zone identified by said zone switchmeans for illuminating said lamp matrix array in accordance with saidstored availability information in an aircraft zone selected by saidzone selector switches.

2. A combination as in claim 1 wherein said lamp illumination meanscomprises means for decoding the seat availability information stored insaid circulating memory, means for gating the decoded seat availabilityinformation corresponding to the selected zone of the aircraft toproduce a lamp video signal, and means for illuminating said lamps atthe console in accordance with said video information.

3. A combination as in claim 1 further comprising a digital printer ateach console, said printer including a plurality of printing modulesincluding modules each associated with a different one of said zone, rowand seat selector switches, and means for positioning said associatedprint modules to a state corresponding to that dictated by saidassociated switch means.

4. A combination as in claim 3 further comprising comparator means forproducing a comparison output signal responsive to a coincidence betweenselected outputs of said counter and said zone, row and seat switches,and means responsive to a comparison signal, to a particulr setting ofsaid mode selector switch in a selected console and to availabilityinformation stored in said circulating memory for causing said printerto print.

5. A combination as in claim 4 further comprising means responsive toeach print signal for changing the availability information in saidcirculating memory at a location corresponding to the seat identified bysaid counter to an unavailable state.

6. In combination in a digital electronic boarding system for allottingseats in an enclosure wherein said seats are subdivided into zones eachcorresponding to a different section of the enclosure, a centralprocessor, at least one keyboard unit, buss means connecting eachkeyboard unit with said central processor, each of aid keyboard unitsincluding plural seat availability display elements, and a plurality ofzone selector switches, a memory included in said central processor forstoring availability information characterizing said seats in saidenclosure, and means for illuminating said display elements inaccordance with the availability information stored in said memorycorresponding to the seating zone defined by said zone selectorswitches.

7. A combination as in claim 6 further comprising a digital printerassociated with each of said keyboard units, a printing moduleassociated with said zone selector switches at each of said keyboardunits, and mans for continuously maintaining said print module in astate signaled by said zone switches.

8. A combination as in claim 7 wherein each of said zone selectorswitches includes an output contact pair, and said print module includesa commutator and plural discrete connection positions each electricallyconnected to the contact pair associated with a different one of saidzone selector switches.

9. A combination as in claim 6 wherein each of said keyboard unitsfurther comprise a plurality of row switches for defining a row withinseating zone selected by said zone selector switches associatedtherewith.

10. A combination as in cliam 9 wherein each of said keyboard unitsfurther includes a plurality of seat selector switches.

11. A combination as in claim 6 wherein said central processor includesmeans for sequentially and cyclically polling each keyboard unit foroperatively connecting the selected keyboard unit for bilateralcommunication with said central processor via said buss means.

12. A combination as in claim 6 wherein said display elementilluminating means comprises means for generating a serial video digitstream comprising availability information for each seat within the zoneof the enclosure selected by said zone switches, means for generating aserial clock byte stream, counting and decoding means at each of saidkeyboard units responsive to said clock pulse stream for sequentiallyselecting each of said keyboard unit display elements, and means forselectively activating the display element selected by said counting anddecoding means in accordance with said video signal.

13. A combination as in claim 12, further comprisng counter menas forsequentially and cyclically polling said keyboard units, and meansresponsive to said polling means for selectively producing intermittentillu mination of selected keyboard display elements.

14. A combination as in claim 13, wherein said intermittent illuminatingmeans comprises divider means for passing selected seat availabilitysignals to said video digit stream only during selected polling cycles.

15. A combination as in claim 14, further comprising row and seatselector switches at each said keyboard units, means for sequentiallyand cyclically polling each of said keyboard units, said centralprocessor including means responsive to particular activated ones ofsaid zone, row, and seat switches at a polled keyboard unit forinterrogating said memory to determine the availability of the seatidentified by said switches, and means responsive to said seat beingavailable for allotting said seat.

16. A combination as in claim 15, wherein said central processor furthercomprises means responsive to a seat being allotted by said seatallotting means for changing the status of said allotted seat in saidmemory to an unavailable status.

17. A combination as in claim 16, further'comprising means for writingseat availability information into said memory.

18. A combination as in claim 17, wherein said seat availability writingmeans comprises a mode switch at each of said keyboard units, aplurality of availablity code registers at said central processor, andmeans responsive to the particular position of said mode switch at apolled keyboard unit for gating the contents of a selected one of saidavailability code registers to said memory, said memory addressreceiving said grated availability code information being defined byswitching means at said polled console.

19. A combination as in claim 17, wherein said writing means comprisesinformation storage means connected to said central processor via saidbus means.

20. A combination as in claim 6, wherein each of said consoles furthercomprises a plurality of row selector switches, wherein said memoryincludes an information field for each row for identifying a keyboardunit selecting that row, and means responsive to an activatedcombination of said zone and row selector switches for writing theidentity of the keyboard unit including said switches into saidcorresponding identification field in said memory.

21. A combination as in claim 20, wherein said central processorincludes means responsive to one of said keyboard information fieldsidentifying a keyboard unit and said zone and row switches at theidentified keyboard unit no longer selecting said row for clearing saidkeyboard unit identification field.

l l l 4 k

1. In combination in a digital electrical system for issuing airlineboarding passes and for effecting seat assignments in an aircraft, saidaircraft seats being identified by a zone designation, a row within azone, and a seat within a row, comprising a central processor, at leastone console, plural conductor system buss means connecting saidprocessor with each of said consoles, each of said consoles including amatrix array of lamps, a plurality of zone selector switches, aplurality of row selector switches, a plurality of seat selectorswitches, and a mode selector switch, console selector means forsequentially and cyclically selecting each of said consoles, a moderegister, means for encoding the mode selector switch position at aselected console, means for inserting said mode switch encoding signalsin said mode register, zone, row and seat registers in said centralprocessor, means for inserting signals representative of siad zone andseat switches assemblies in said console in said zone, row and seatregisters, respectively, a circulating memory for storing and cyclicallypresenting at output terminals thereof signals indicative of theavailability of all aircraft seats, a system oscillator and counter foridentifying the information present at said circulating memory output,and means responsive to an aircraft zone identified by said zone switchmeans for illuminating said lamp matrix array in accordance with saidstored availability information in an aircraft zone selected by saidzone selector switches.
 2. A combination as in claim 1 wherein said lampillumination means comprises means for decoding the seat availabilityinformation stored in said circulating memory, means for gating thedecoded seat availability information corresponding to the selected zoneof the aircraft to produce a lamp video signal, and means forilluminating said lamps at the console in accordance with said videoinformation.
 3. A combination as in claim 1 further comprising a digitalprinter at each console, said printer including a plurality of printingmodules including modules each associated with a different one of saidzone, row and seat selector switches, and means for positioning saidassociated print modules to a state corresponding to that dictated bysaid associated switch means.
 4. A combination as in claim 3 furthercomprising comparator means for producing a comparison output signalresponsive to a coincidence between selected outputs of said counter andsaid zone, row and seat switches, and means responsive to a comparisonsignal, to a particulr setting of said mode selector switch in aselected console and to availability information stored in saidcirculating memory for causing said printer to print.
 5. A combinationas in claim 4 further comprising means responsive to each print signalfor changing the availability information in said circulating memory ata location corresponding to the seat identified by said counter to anunavailable state.
 6. In combination in a digital electronic boardingsystem for allotting seats in an enclosure wherein said seats aresubdivided into zones each corresponding to a different section of theenclosure, a central processor, at least one keyboard unit, buss meansconnecting each keyboard unit with said central processor, each of aidkeyboard units including plural seat availability display elements, anda plurality of zone selector switches, a memory included in said centralprocessor for storing availability information characterizing said seatsin said enclosure, and means for illuminating said display elements inaccordance with the availability information stored in said memorycorresponding to the seating zone defined by said zone selectorswitches.
 7. A combination as in claim 6 further comprising a digitalprinter associated with each of said keyboard units, a printing moduleassociated with said zone selector switches at each of said keyboardunits, and mans for continuously maintaining said print module in astate signaled by said zone switches.
 8. A combination as in claim 7wherein each of said zone selector switches includes an output contactpair, and said print module includes a commutator and plural discreteconnection positions each electrically connected to the contact pairassociated with a different one of said zone selector switches.
 9. Acombination as in claim 6 wherein each of said keyboard units furthercomprise a plurality of row switches for defining a row within seatingzone selected by said zone selector switches associated therewith.
 10. Acombination as in cliam 9 wherein each of said keyboard units furtherincludes a plurality of seat selector switches.
 11. A combination as inclaim 6 wherein said central processor includes means for sequentiallyand cyclically polling each keyboard unit for operatively connecting theselected keyboard unit for bilateral communication with said centralprocessor via said buss means.
 12. A combination as in claim 6 whereinsaid display element illuminating means comprises means for generating aserial video digit stream comprising availability information for eachseat within the zone of the enclosure selected by said zone switches,means for generating a serial clock byte stream, counting and decodingmeans at each of said keyboard units responsive to said clock pulsestream for sequentially selecting each of said keyboard unit displayelements, and means for selectively activating the display elementselected by said counting and decoding means in accordance with saidvideo signal.
 13. A combination as in claim 12, further comprisngcounter menas for sequentially and cyclically polling said keyboardunits, and means responSive to said polling means for selectivelyproducing intermittent illumination of selected keyboard displayelements.
 14. A combination as in claim 13, wherein said intermittentilluminating means comprises divider means for passing selected seatavailability signals to said video digit stream only during selectedpolling cycles.
 15. A combination as in claim 14, further comprising rowand seat selector switches at each said keyboard units, means forsequentially and cyclically polling each of said keyboard units, saidcentral processor including means responsive to particular activatedones of said zone, row, and seat switches at a polled keyboard unit forinterrogating said memory to determine the availability of the seatidentified by said switches, and means responsive to said seat beingavailable for allotting said seat.
 16. A combination as in claim 15,wherein said central processor further comprises means responsive to aseat being allotted by said seat allotting means for changing the statusof said allotted seat in said memory to an unavailable status.
 17. Acombination as in claim 16, further comprising means for writing seatavailability information into said memory.
 18. A combination as in claim17, wherein said seat availability writing means comprises a mode switchat each of said keyboard units, a plurality of availablity coderegisters at said central processor, and means responsive to theparticular position of said mode switch at a polled keyboard unit forgating the contents of a selected one of said availability coderegisters to said memory, said memory address receiving said gratedavailability code information being defined by switching means at saidpolled console.
 19. A combination as in claim 17, wherein said writingmeans comprises information storage means connected to said centralprocessor via said bus means.
 20. A combination as in claim 6, whereineach of said consoles further comprises a plurality of row selectorswitches, wherein said memory includes an information field for each rowfor identifying a keyboard unit selecting that row, and means responsiveto an activated combination of said zone and row selector switches forwriting the identity of the keyboard unit including said switches intosaid corresponding identification field in said memory.
 21. Acombination as in claim 20, wherein said central processor includesmeans responsive to one of said keyboard information fields identifyinga keyboard unit and said zone and row switches at the identifiedkeyboard unit no longer selecting said row for clearing said keyboardunit identification field.